This invention relates generally, as indicated, to a landing gear mechanism and more particularly to a restrictor assembly for substantially reducing or eliminating high damping loads as the landing gear negotiates bumps to permit high performance aircraft to operate on relatively rough runways.
Typically, landing gears for high performance aircraft such as operated by the military are not designed to operate on rough runways made rough, for example, as a result of temporary repairs to bomb damaged areas and the like.
It is possible to make the gear effective at heavy take-off weight and still provide the required shock strut stroke during landing to absorb the required amount of landing energy to prevent damage to the gear during landing on rough runways by providing the gear with different low spring rate load ranges as described in applicant's copending U.S. patent application Ser. No. 499,217, filed May 31, 1983, now U.S. Pat. No. 4,552,324, dated Nov. 12, 1985, the disclosure of which is incorporated herein by reference.
The landing gear of such copending application can also be made to discriminate between shock strut extension during normal ground roll and extension as the strut tire follows a sudden recess during forward travel, prevent cavitation in the lower piston chamber of the gear as the gear extends, and provide for piston rebound damping as the piston approaches the end of its stroke during full extension.
In addition, provision can be made in the gear of such copending application for substantially reducing or eliminating high damping loads as the landing gear negotiates bumps. Briefly, this is accomplished by the opening of a taxi instroke bypass valve as soon as the landing energy stroke is complete to allow fluid to pass more freely from the lower piston chamber to the upper piston chamber, bypassing the primary flow orifice.
The landing gear of the present invention may also include the various features disclosed in such copending application. However, the present landing gear includes a simpler mechanism for reducing or substantially eliminating the high damping loads that might otherwise take place as the gear negotiates bumps. Also, such mechanism is better suited to being packaged into a smaller space than the corresponding mechanism of such copending application.